i'll answer your questions ((to the best of my knowledge)) in the order you asked:
1. My brother and i both have KM's ((a pear and an aurora, 36")) and they smoke beautifully.
The regular km is 90 at *************, and for an extra 10 bucks you can get the pear, but the only difference being the pear shaped insert. just for looks is the only difference, to my knowledge.
2. DEFINITELY invest in a fatty hose. I use a KM and it's beautiful. effortless. but many ppl on here get razaan or namour (sp?) and are supposed to be good quality.
KM hoses at CH.com are 20
Many people would also advise to get a phunnel bowl, but i dont have one nor know how to use one, so i cant truly recommend it.
3. idk, can't answer that. shoot a message to john (username *************) and see what he's got coming in
4. in my opinion, as well as most of the ppl here, *************.com is the way to go. Hookah-shisha.com is supposed to be legit as well. check the vendor section for more reviews.
as far as getting a two hose: I prefer one hose hookahs. Fewer parts, easier to manage. Plus more hoses = greater chance of tipping from someone not paying attention and tugging. I regularly smoke w/ 5 or 6 people from a one hose KM and it's pretty tits. we use the hit, hit, hit pass rule. just my experience.
so a KM pear + a big hose ~ 120 dollars. that'll leave you with some money to pick up some coals/shisha.
i hope this helps
welcome to the community btw.